Light coupling assembly for use in a medical instrument, system and method

ABSTRACT

A light coupling assembly for use in providing light for illuminating an area of a patient&#39;s anatomy during the use of a medical instrument such as, for example, a laryngoscope is disclosed herein. The light coupling assembly includes a first light conveyance member having an input end for receiving light and an output end cooperating with the instrument in a way which illuminates the area with the light. A second light conveyance member includes an input end and an output end. The input end of the second member is positioned in optical communication with a source of light which also generates heat. A coupling arrangement is connected with the first and second members for positioning the input end of the first member in thermally isolated optical communication with the output end of the second member such that light from the first member is initially coupled to the second member in a way which prevents heat produced by the light source from damaging the first member. A system utilizing the light coupling assembly as one of its components and an associated method are also disclosed. The system provides for remote viewing of the illuminated anatomy of the patient on a monitor.

BACKGROUND OF THE INVENTION

The present invention relates generally to a light coupling assembly foruse with medical instruments. More particularly, it relates to a lightcoupling assembly and associated system specifically configured toreceive light from a remote source of light, which also generates heat,and to then direct this light to an instrument such as, for example, anendoscope such as a laryngoscope, through a fiber-optic cable in a waywhich prevents heat generated by the light source from damaging thefiber-optic cable.

Systems including a light source and associated equipment for couplinglight from a light source to a medical instrument are known in the art.Typically, such systems utilize glass fiber-optic cable to couple thesource light to the instrument and, thereafter, illuminate a particulararea of a patient's anatomy. A medical practitioner can then view theilluminated area during a particular procedure by using a viewingarrangement such as a fiber-optic cable with an attached eyepiece. Sucha prior art viewing arrangement is shown in U.S. Pat. No. 4,337,761,issued to the inventor of the present invention, in association with alaryngoscope so that an image of the illuminated area is provided at theeyepiece. In using such past systems, however, the subject anatomicalarea is generally rather dimly illuminated because relatively weak lightsources are used, as these sources are typically powered by batterieshoused, for example, in the handle of the instrument. More recently,external light sources have been provided. These sources typicallycouple light from a remote light source directly into a glassfiber-optic cable. However, illumination levels have not beendramatically improved by such external light sources. The relatively lowlight levels have been acceptable only because they are compensated forby the relatively sensitive eye of the practitioner directly viewing theimage at the eyepiece.

Recent advances in the field of video imagery, including theavailability of compact low cost CCD video cameras, have resulted in afundamental change in the way practitioners may perform such procedures.It is now highly possible to directly couple a video camera to aneyepiece or other such arrangement whereby to allow a practitioner toview a procedure on a video monitor. This technique is advantageous fora number of reasons. For one, such a system is extremely useful in aninstructional environment for training new practitioners. Trainees maybe present for observation as the procedure is being performed or,alternatively, the procedure may be recorded for later viewing in aclassroom environment. Additionally, a permanent video record of theprocedure may prove to be useful for insurance and other purposes.

Unfortunately, the use of even the latest video camera requiresrelatively bright illumination of the patient's anatomy. It would seemthat the simple expedient of increasing the brightness of the lightsource in the above described external source would resolve thisproblem. However, the light source also generates heat and asignificantly brighter light source, which is suitable for use with avideo camera, produces much more heat than former light sources whichwere used in conjunction with direct viewing by the human eye. In fact,the heat produced is increased to a level at which direct exposuredamages plastic fiber-optic cables of this type which are desirable foruse in this application. In prior art systems utilizing external lightsources, such cables are positioned in close proximity with the lightsource to initially receive light for transmission to the instrument.This type of arrangement is not suitable for use with light sourcescontemplated for use with state of the art video viewing arrangementssince the plastic fiber optic cable will ultimately be damaged by thegenerated heat of the light source. Substitution of other heat resistantlight conductive materials such as, for example, glass or quartz inplace of the plastic fiber-optic cable is also problematic. Thesealternate materials, while being less sensitive to heat, are alsocharacterized by high internal light transmission losses. In addition,they are extremely expensive and have a tendency to break due to theirmultiple tiny fiber construction. Therefore, the use of these alternatematerials, as a direct substitute for plastic fiber-optic cable, isself-defeating in that transmission losses are high enough that itbecomes difficult to achieve acceptable illumination levels, withoutusing very large composite bundles, and even when using the muchbrighter light sources contemplated by the present invention. It shouldbe added that composite bundles have dead space between the fibers whichsignificantly decrease their functional cross-section. This is not trueof solid plastic fibers.

The present invention resolves the foregoing difficulties by providing ahighly advantageous light coupling assembly which is adapted for usewith an intense, heat producing light source and which couples thisintense light to a low loss fiber-optic cable in a hybrid light pathwithout subjecting the latter to damaging levels of heat produced by thelight source; the cable can be made of a heat sensitive material, suchas plastic, rendering the cable both light weight and disposable.

SUMMARY OF THE INVENTION

As will be described in more detail hereinafter, there is disclosedherein a light coupling assembly for use in providing light forilluminating an area of a patient's anatomy during the use of a medicalinstrument such as, for example, a laryngoscope. A system utilizing thelight coupling assembly as one of its components and an associatedmethod are also disclosed.

In accordance with the present invention, the light coupling assemblyincludes a first light conveyance member having an input end forreceiving light and an output end cooperating with the instrument in away which illuminates the area with the light. A second light conveyancemember includes an input end and an output end. The input end of thesecond member is adapted for positioning in optical communication with asource of light which also generates large amounts of heat, generallyspeaking. The second member is constructed of a material which is lesssusceptible to the heat than the material from which the first member isconstructed. A coupling arrangement is connected with the first andsecond members for positioning the input end of the first member inoptical communication with the output end of the second member such thatlight from the first member is coupled to the second member and thefirst member is thermally isolated from the light source in a way whichprevents heat produced by the light source from damaging the firstmember.

In a first feature, the coupling arrangement is in thermal communicationwith the second member to receive heat generated by the light source viathe second member.

In a second feature, the coupling arrangement includes an integrallyformed heat sink for dissipating heat received via the second memberinto the ambient environment.

A system for use in a medical procedure which requires illumination ofan area of a patient's anatomy is also disclosed herein. The systemincludes an instrument adapted for performing the procedure and a lightsource which generates light and heat. A first light conveyance memberincludes an input end for receiving light and an output end cooperatingwith the instrument in a way which illuminates the area with the light.A second light conveyance member includes an input end and an outputend. The input end of the second member is adapted for positioning inoptical communication with the light source to initially receive thislight. The second member is constructed of a material which is lesssusceptible to the heat than the material from which the first member isconstructed. A coupling arrangement is connected with the first andsecond members for positioning the input end of the first member inoptical communication with the output end of the second member such thatlight from the second member is coupled to the first member. The firstmember is thermally isolated from the light source in a way whichprevents heat generated by the light source from damaging the firstmember.

In a first feature of the system, the instrument is a laryngoscope whichincludes a viewing arrangement for remotely viewing the illuminatedarea.

In a second feature of the system, the viewing arrangement includes acamera adapter. A video camera is mounted on the camera adapter. Amonitor is connected to the camera such that an individual, who isoperating the system, can remotely view the illuminated area on themonitor.

In a third feature of the system, the light source is positioned in anenclosure which supports the coupling arrangement such that the inputend of the second member is in optical communication with the lightsource.

In a method of providing light for illuminating an area of a patient'sanatomy in association with the use of a medical instrument such as, forexample, a laryngoscope, light is produced remotely from the instrumentby using a light source which also generates heat. A first lightconveyance member is provided having an input end and an output endwhich cooperates with the instrument for illuminating the area withlight. A second light conveyance member is provided having an input endand an output end such that the second member is formed from a materialwhich is less susceptible to heat than the material from which the firstmember is formed. The input end of the second member is positioned inoptical communication with the light source to initially receive thelight and thereafter emit the light from its output end. The input endof the first member is positioned adjacent the output end of the secondmember such that light emitted from the second member is coupled to theinput end of the first member in a way which thermally isolates thefirst member from the light source whereby to prevent the generated heatfrom damaging the first member.

In one preferred method, the coupling arrangement is provided in thermalcommunication with the second member to receive heat produced by thelight source via the second member and, thereafter, dissipate the heatfrom the coupling arrangement into the ambient environment.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be understood by reference to the followingdetailed description taken in conjunction with the drawings, in which:

FIG. 1 is a cross-sectional elevational view of a light couplingassembly manufactured in accordance with the present invention for usein coupling relatively intense illuminating light to a medicalinstrument from a heat generating light source; and

FIG. 2 illustrates the light coupling assembly of the present inventionas part of an overall system for providing light to a medical instrumentfor illuminating a portion of a patient's anatomy using light which isproduced by a light source within the system which also generates heat,and for remotely viewing the illuminated anatomy on a monitor screen.

DETAILED DESCRIPTION OF THE INVENTION

A light coupling assembly for use with a medical instrument and a systemwhich utilizes the coupling assembly along with an associated method aredisclosed herein. Attention is immediately directed to FIG. 1 whichillustrates a light coupling assembly, generally indicated by referencenumber 10, manufactured in accordance with the present invention. Lightcoupling assembly 10 includes an elongated coupler 16 having opposingfirst and second ends 18 and 20, respectively, and defining athrough-passage 22 therebetween. For purposes of simplicity ofmanufacture, through-passage 22 is generally formed having a circularcross-section (not shown), although other shapes are also suitable.Coupler 16 also includes an integrally formed circumferential heat sink24 having a plurality of heat dissipating fins 26. A circumferentialthreaded flange 28 is also formed integrally with coupler 16 and islocated adjacent to heat sink 24. The purposes of heat sink 24 andflange 28 will be described at appropriate points in the followingdiscussion. Coupler 16 is formed from a heat conductive material suchas, for example, aluminum or an aluminum alloy, although many other heatconductive materials may be used in accordance with the presentinvention.

Continuing to refer to FIG. 1, a first light conveyance member 30includes an input end 32 and an output end 33. First member 30 isgenerally a circular cross-section plastic fiber-optic cable of the typewhich transmits light with very low losses and which is also typicallydamaged by exposure to heat at relatively low temperatures. As will beseen hereinafter, and in accordance with one feature of the presentinvention, the overall light coupling assembly is configured in a waywhich isolates first light conveyance member 30 from heat which candamage the member when the assembly is being used. To that end, inputend 32 of cable 30 is captured within a heat isolator 34 having a wallthickness t. Heat isolator 34 is, in turn, captured withinthrough-passage 22 at first end 18 of coupler 16. Heat isolator 34 andinput end 32 may be retained in position by, for example, a friction fitor a suitable adhesive (not shown) and is cross-sectionally configuredto conform to through-passage 22 and first member 30. Various materialscan be used to form heat isolator 34 including ceramics which exhibitsufficiently low coefficients of thermal energy transfer. It is alsoanticipated that many other arrangements may be produced for retaininginput end 32 of first light conveyance member 30 within coupler 16. Forexample, first end 18 of coupler 16 can be cooperatively configured withheat isolator 34 in a snap-fitting arrangement such that first member 30and heat isolator 34 are readily removable to facilitate, for example,switching to a different instrument. These alternative arrangements areall considered to be within the scope of the invention.

A second light conveyance member 36 includes an input end 38, an outputend 40 and a length L therebetween. Second member 36 is captured inthrough-passage 22 of coupler 16 such that input end 38 is flush withsecond end 20 of coupler 16 and the such that second member 36 is inthermal communication along its length L with coupler 16. To maximizethermal communication, second member 36 is generally configured ashaving the same cross-sectional shape, circular in the present example,as through-passage 22. Second light conveyance member 36 may be held inposition within through-passage 22 by, for example, a friction fit, byheat conductive glue (not shown) which is also heat resistant or by anyother arrangement (not shown) which maintains thermal communicationbetween second member 36 and coupler 16. An infrared filter 42 isfixedly mounted on second end 20 of coupler 16 by, for example, a heatresistant adhesive 44 or by such items as mechanical fasteners (notshown) which extend through filter 42 and into coupler 16. Second lightconveyance member 36 can be formed from a variety of heat resistantmaterials such as, for example, glass or quartz.

Still referring to FIG. 1, coupler 16 supports first and second lightconveyance members, 30 and 36 respectively, such that input end 32 offirst member 30 is in thermally isolated optical communication withoutput end 40 of second member 36 through a chamber 46 having a lengthd. Chamber 46 is cooperatively defined by input end 32 of first member30, output end 40 of second member 36 and an end portion 48 of heatisolator 34. Chamber 46 may be evacuated, filled with air, or filledwith a material such as a light transmissive, thermally isolatingadhesive (not shown) such that first and second members, 30 and 36respectively, remain in thermally isolated optical communication whenthe assembly is in use. With regard to length L of second member 36, twoconsiderations govern. First, materials such as glass and quartz, fromwhich second member 36 is formed, exhibit significant losses when usedas conductors of light. Therefore, length L should be kept as short aspossible in order to avoid unnecessary light attenuation. However, as asecond consideration, it must be long enough to dissipate sufficientheat in order to protect first member 30. The significance of theforegoing design considerations, particularly with regard to thermalisolation, will become evident in conjunction with a discussion below ofone overall system which uses light coupling assembly 10 in accordancewith a method of the present invention.

Turning now to FIG. 2, light coupling assembly 10 is illustrated asforming part of an overall system 50 for use in a medical procedurewhich requires illumination of an area 52 of the anatomy of a patient54. System 50 includes a light source 56 positioned within an enclosure58. Flange 28 on light coupling assembly 10 is removably engaged in athreaded aperture 60 formed by enclosure 58, whereby to positioninfrared filter 42 in close proximity with light source 56 and toposition heat sink 24 outside the enclosure and exposed to the ambientenvironment. Alternatively, flange 28 can be removably engaged to anyone of a number of commercially available adapters (not shown) whichwill interface with their respective light sources. Light source 56 is arelatively intense emitter of light 62 and is also a significant sourceof heat 64. A variety of different types of sources are useful forproviding light in the present application such as, for example, a Storzlight source. Following emission, light 62 is incident upon infraredfilter 42 of light coupling assembly 10. Filter 42 removes infraredcomponents of emitted light 62 so as to permit a portion 66 of the lightto be picked up by input end 38 of second light conveyance member 36. Itis desirable to initially eliminate infrared components of light 62using such a filter since these components can generate damaging heat atsucceeding points within system 50. Infrared filter 42 can be formedfrom materials which are well known in the art.

Continuing to refer to FIG. 2, light 66 is conducted through secondmember 36 to be emitted at its output end. Light 66 is then coupled toinput end 32 of first light conveyance member 30 through length d (seeFIG. 1) of chamber 46. As previously mentioned, the chamber may beevacuated, contain air, or contain a thermally isolating material suchas a suitable, optically-clear adhesive. After passing through chamber46, light 66 is picked up by input end 32 or first light conveyancemember 30 and then conducted by the latter to its output end 33. In thepresent example, output end 33 is attached directly to a laryngoscope 68whereby light 66 is emitted from output end 33 to illuminate area 52 ofthe anatomy of patient 54 during an intubation procedure. However, it isto be understood that laryngoscope 68 is shown herein for illustrativepurposes only, and that other instruments such as, for example, othertypes of endoscopes (not shown) may be used as part of the system of thepresent invention. Furthermore, it should also be appreciated thatoutput end 33 of first member 30 may couple light to an instrument inmany other ways. For instance, output end 33 may attach to theinstrument in a way which couples light to a light input port providedon a handle or other portion of the instrument. The coupled light isthen conducted by separately provided fiber-optic or other such elementswhich cooperate to receive the light and ultimately emit it onto thepatient's anatomy.

Laryngoscope 68 further includes a viewing arrangement 70 for providingan image of illuminated area 52 at a camera adapter 72 through a viewingmember 74 that is positioned on the laryngoscope. A compact video camera76 is mounted on camera adapter 72 to produce a video signal which isthereafter transmitted through a cable 78 to a monitor 80. Monitor 80includes a viewing screen 82 on which an image of the subject patient'sanatomy is remotely reproduced from the video signal. It should also bementioned that camera adapter 72 may be configured such that camera 76can be removed therefrom and the image presented within the cameraadapter can then be directly viewed by a practitioner, as with a priorart eyepiece.

Returning now to a discussion of thermal design considerations relevantto light coupling assembly 10, light source 56 is also a significantgenerator of heat 64, as previously noted. Infrared filter 42 and aportion 84 of coupler 16 are exposed either directly or indirectly tothis heat within enclosure 58. Because coupler 16 is in thermalcommunication with second light conveyance member 36, heat 64 is alsotransferred thereto. In accordance with the present invention, lightcoupling assembly 10 is specifically configured so as to prevent firstlight conveyance member 30 from being damaged by heat 64.

Still referring to FIG. 2, protection of first member 30 from heat isaccomplished in two significant ways by the arrangement of lightcoupling assembly 10. First, thermal isolation of first light conveyancemember 30 from the overall assembly is provided. This isolation isaccomplished through the use of heat isolator 34 in conjunction withchamber 46 whereby to thermally decouple the cable from the remainingassembly. Second, heat 64 is dissipated directly into the ambientenvironment and away from the first light conveyance member by coupler16. Specifically, coupler 16, in being formed from aluminum, is anexcellent thermal conductor. Heat 64, received by portion 84 of thecoupler within enclosure 58, is conducted along a thermal path A (asindicated by arrows), directly to heat sink 24 for dissipation into theambient surroundings by fins 26. Heat 64, received by second lightconveyance member 36, is conducted along a thermal path B (alsoindicated by arrows) directly to heat sink 24 for dissipation therefrom,since second member 36 is in direct thermal communication with coupler16. The combination of thermal isolation of first member 30 from heat 64in conjunction with the ability of the overall light coupling assemblyto dissipate the heat away from first member 30 along paths A and B,whereby to control the temperature of the overall assembly, results inexposure of input end 32 of first light conveyance member 30 to greatlyreduced heat levels, even in the case where a bright, heat producinglight source is used. Moreover, length L of second member 36 (seeFIG. 1) is short enough to minimize attenuation of light passing throughthe member, yet long enough to ensure adequate dissipation of heat intoheat sink 24 along path B.

The present invention advantageously provides for effectively couplinglight produced by a brilliant, heat generating source to an instrument.The light is transferred to the instrument with low transmission lossesalong a hybrid light conducting path which initially includes a couplingassembly that is exposed to the heat and picks up light produced by thelight source. Thereafter, the light is transferred by light couplingassembly 10 to a low loss fiber-optic cable without exposing the latterto unacceptable levels of heat such that an area of a patient's anatomycan be illuminated with light levels not previously seen in an externallight source, remote viewing arrangement. The subject area issufficiently illuminated for viewing using a video camera and associatedmonitor. An additional advantage resides in the fact that the lightcoupling assembly of the present invention is highly reliable since theassembly is constructed in a way which utilizes no moving parts.

It should also be mentioned that the light coupling assembly andassociated system can be modified in a number of ways to suit specificapplications based on, for example, heat generated by different types oflight sources. For instance, in cases where a particularly hot lightsource is used, thermal isolation of first light conveyance member 30can be further improved by increasing length d of chamber 46 and/orincreasing thickness t of heat isolator 34. Still further improvementcan be obtained by modifying the assembly to increase heat dissipationtherefrom. This can be accomplished by, for example, increasing thenumber or size of fins 26 which make up heat sink 24.

Since the light coupling assembly and associated system disclosed hereinmay be modified in an unlimited number of ways, it should be understoodthat the present invention may be embodied in many other specific formswithout departing from the spirit or scope of the present invention.Therefore, the present examples and methods are considered asillustrative and not restrictive, and the invention is not to be limitedto the details given herein, but may be modified within the scope of theappended claims.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:
 1. A light coupling assembly for use inproviding light for illuminating an area of a patient's anatomy duringthe use of a medical instrument such as, for example, a laryngoscope,said assembly comprising:a) a first light conveyance member having aninput end for receiving light and an output end cooperating with saidinstrument in a way which illuminates said area with said light, saidfirst member being constructed of a first material; b) a second lightelongated conveyance member having an input end and an output end, saidinput end of said second member being adapted for positioning in opticalcommunication with a source of said light which also generates heat,said second member being constructed of a second material which is lesssusceptible to said heat than said first material; and c) a couplingarrangement including an elongated coupler connected with the first andsecond members for positioning said input end of the first member inoptical communication with the output end of the second member such thatlight from said first member is coupled to said second member and saidfirst member is thermally isolated from said light source in a way whichprevents said heat from damaging the first member.
 2. A light couplingassembly in accordance with claim 1 wherein said coupling arrangement isin thermal communication with said second member to receive saidgenerated heat via the second member.
 3. A light coupling assembly inaccordance with claim 2 wherein said coupling arrangement includes anintegrally formed heat sink for dissipating said generated heat receivedby the coupling arrangement into the ambient environment.
 4. A lightcoupling assembly in accordance with claim 3 wherein said heat sink andelongated coupler of said coupling arrangement which are in thermalcommunication with said second member are formed from a materialconsisting essentially of aluminum.
 5. A light coupling assembly inaccordance with claim 1 wherein said first member is an elongatedplastic fiber-optic material.
 6. A light coupling assembly in accordancewith claim 1 wherein said second light elongated conveyance member isformed from quartz.
 7. A light coupling assembly in accordance withclaim 1 wherein said second light elongated conveyance member is formedfrom glass.
 8. A light coupling assembly in accordance with claim 1wherein said input end of said first member is positioned by saidcoupling arrangement in a way which thermally isolates the first memberfrom the second member.
 9. A light coupling assembly in accordance withclaim 8 wherein said coupling arrangement includes a thermally isolatingmaterial which supports said input end of said first member to providethermal isolation of said first member from said generated heat.
 10. Alight coupling assembly in accordance with claim 9 wherein saidthermally isolating material is ceramic.
 11. A light coupling assemblyin accordance with claim 1 wherein said input end of said first memberis separated from said output end of said second member by a chamberwhich is cooperatively defined by the first member, the second memberand the coupling arrangement.
 12. A light coupling assembly inaccordance with claim 11 wherein said chamber is evacuated.
 13. A lightcoupling assembly in accordance with claim 11 wherein said chamber isfilled by air.
 14. A light coupling assembly in accordance with claim 11wherein said chamber is filled by a thermally isolating, lighttransmissive material.
 15. A light coupling assembly in accordance withclaim 14 wherein said material is glue.
 16. A light coupling assembly inaccordance with claim 1 wherein said input end of said second memberincludes an infrared filter positioned to prevent infrared components ofsaid light from reaching said instrument.
 17. A system for use in amedical procedure which requires illumination of an area of a patient'sanatomy, said system comprising:a) a light source which generates lightand heat; b) an instrument adapted for performing said procedure; c) afirst light conveyance member having an input end for receiving saidlight and an output end and cooperating with said instrument in a waywhich illuminates said area with said light, said first member beingconstructed of a first material; d) a second light elongated conveyancemember having an input end and an output end, said input end of saidsecond member being adapted for positioning in optical communicationwith said light source to initially receive said light, said secondmember being constructed of a second material which is less susceptibleto said heat than said first material; and e) a coupling arrangementincluding an elongated coupler connected with the first and secondmembers for positioning said input end of the first member in opticalcommunication with the output end of the second member such that lightfrom said second member is coupled to said first member and said firstmember is thermally isolated from said light source in a way whichprevents said heat from damaging the first member.
 18. A system inaccordance with claim 17 wherein said coupling arrangement is in thermalcommunication with said second member to receive said generated heat viathe second member.
 19. A system in accordance with claim 18 wherein saidcoupling arrangement includes an integrally formed heat sink fordissipating said generated heat into the ambient environment.
 20. Asystem in accordance with claim 19 wherein said heat sink and elongatedcoupler of said coupling arrangement which are in thermal communicationwith said second member are formed from a material consistingessentially of aluminum.
 21. A system in accordance with claim 17wherein said first member is an elongated plastic fiber-optic material.22. A system according to claim 17 wherein said instrument is alaryngoscope including a viewing arrangement for remotely viewing saidilluminated area.
 23. A system according to claim 22 wherein saidviewing arrangement includes a camera adapter and wherein said systemincludes a video camera mounted on said camera adapter and a monitorconnected to said camera such that an individual operating the systemcan remotely view said illuminated area on said monitor.
 24. A systemaccording to claim 17 including an enclosure in which said light sourceis positioned and wherein said coupling arrangement is supported by saidenclosure such that said input end of said second member is in opticalcommunication with the light source.
 25. A system in accordance withclaim 17 wherein said input end of said first member is positioned bysaid coupling arrangement in a way which thermally isolates the firstmember from the second member.
 26. A system in accordance with claim 25wherein said coupling arrangement includes a thermally isolatingmaterial which supports said input end of said first member to providethermal isolation of said first member from said generated heat.
 27. Asystem in accordance with claim 26 wherein said thermally isolatingmaterial is ceramic.
 28. A system in accordance with claim 17 whereinsaid input end of said first member is separated from said output end ofsaid second member by a chamber which is cooperatively defined by thefirst member, the second member and the coupling arrangement.
 29. Asystem in accordance with claim 28 wherein said chamber is evacuated.30. A system in accordance with claim 28 wherein said chamber is filledby air.
 31. A system in accordance with claim 28 wherein said chamber isfilled by a thermally isolating, light transmissive material.
 32. Asystem in accordance with claim 31 wherein said material is glue.
 33. Asystem in accordance with claim 17 wherein said second light conveyancemember is formed from quartz.
 34. A system in accordance with claim 17wherein said second light conveyance member is formed from glass.
 35. Asystem in accordance with claim 17 wherein said input end of said secondmember includes an infrared filter positioned to prevent infraredcomponents of said light from reaching said instrument.
 36. A method ofproviding light for illuminating an area of a patient's anatomy inassociation with the use of a medical instrument such as, for example, alaryngoscope, said method comprising the steps of:a) producing lightremotely from said instrument by using a light source which alsogenerates heat; b) providing a first light conveyance member having aninput end and an output end, said output end cooperating with saidinstrument for illuminating said area with said light; c) providing asecond light elongated conveyance member having an input end and anoutput end, said second member being less susceptible to heat than saidfirst member; d) positioning said input end of said second member inoptical communication with said light source to receive said light andthereafter emit the light from said output end; and e) positioning saidinput end of said first member adjacent said output end of said secondmember such that light emitted from said second member is coupled to theinput end of the first member in a way which thermally isolates thefirst member from said light source whereby to prevent said generatedheat from damaging the first member.
 37. A method according to claim 36including the steps of providing a coupling arrangement in thermalcommunication with said second member to receive said heat via thesecond member and thereafter, dissipating said heat from the couplingarrangement into the ambient environment.